Operating Systems - File Systems & Unix/Linux Commands

The finger command in Unix displays information about both local and remote users, including login name, terminal line, idle time, and office location. who shows only logged-in users, whoami shows only current username, and whois queries domain registration databases - not user information.

The rm -r (recursive) command deletes all files and subdirectories within a directory tree. Plain rm only deletes files, not directories. rmdir only removes empty directories, not files or non-empty directories. del is a DOS/Windows command, not Unix/Linux.

The su (substitute user) command is the standard Unix/Linux tool used to switch user accounts, defaulting to the root superuser if no username is provided. The sc command is a Windows service utility, while switch and login do not perform this specific privilege escalation function.

To show the current PID, you should use the command 'echo$$'. The $$ special variable in shell scripting returns the process ID of the current shell. Option B is incorrect because $PID is not a valid variable. Option C is wrong as $USER shows the username, not PID. Option D is incorrect because $user is also not a valid PID variable.

In Unix/Linux systems, the root user has both UID (User ID) and GID (Group ID) set to 0. This is a fundamental system convention - the value 0 uniquely identifies the superuser with unrestricted privileges. Other user and group IDs start from 1 upwards for regular users and system accounts.

In Unix/Linux operating systems, the standard default permission for a newly created directory is octal 755 (rwxr-xr-x), which allows the owner full access and other users read and execute access. Default file permissions are typically 644 (rw-r--r--), with both governed by the user's umask.

Windows Server 2003 Enterprise Edition supported 1 to 8 processors. This was a key differentiator from the Standard Edition which supported 1-2 processors, and the Datacenter Edition which supported 8-32 processors.

A basic disk can contain either 4 primary partitions OR 3 primary partitions plus 1 extended partition. The extended partition can then contain multiple logical drives. Both options A and C correctly describe valid basic disk configurations.

NTFS (New Technology File System) is more secure than FAT file systems because it supports Access Control Lists (ACLs) for fine-grained permissions, file encryption (EFS), disk quotas, file compression, and transactional operations. FAT-12/16/32 have no security features.

Disk quotas are a feature of NTFS, not FAT-32. FAT-32 file systems do not support quota management. Quotas allow administrators to track and control disk space usage per user.